Unusual soot or dark deposits

Fuel, combustion conditions, maintenance needs and system faults can affect deposits. Soot associated with a gas appliance requires appropriately qualified gas-appliance assessment.

Record the fuel, appliance model, last service date and where deposits appear. Keep an existing report or safely taken photograph; avoid disturbing material for a sample.

Keep the appliance model, fuel, previous report and date of last service together. A clear sequence of events can be more useful than deciding in advance which component must be replaced.

For wood systems, request inspection and an explanation of whether routine sweeping or specialised deposit removal is appropriate. Stop use when abnormal deposits or performance suggest a problem.

Request a report that distinguishes what was observed from what remains uncertain. Ask the company to identify any area it could not inspect and whether another trade is needed. If a major repair is proposed, compare a second written scope using the same appliance details and findings.

Do not treat a directory profile, an estimate or this page as clearance to use an appliance. Ask the attending professional what must be resolved before reuse.

Use the local guide to prepare questions about access, building history and the authority responsible for your address. The service brief is national guidance; local permits and current burn restrictions must be checked separately.